Decolorizing glycerin.



'Wlt a to be the glycerin in solution,

I UNITED STATES PATENT car es.

FELIX LINDNER, OF LUDWIGSHAFEN-ON-THE-RHINE, GERMANY, ASSIGNOR TO BADISGHE ANILIN & SODA FABRIK, OF LUDWIGSHAFEN-ON-THE-RHINTE, GER- 'MANY, A CORPORATION OF BADEN.

, nncotonrzme GLYCERIN.

No Drawing.

To all whom it may concern:

Be it known that I, FELIX LINDNER, a Subject of the King of Saxony, residing at Ludwigshafien on the Rhine, Germany, have invented new and useful Improvements in Deeolorizing Glycerin, of which the following is a specification.

The usually employed method of rendering glycerin colorless, or nearly so, is to heat it. with animal charcoal. I have now discovered that the hydrosulfites and the be used for.

formaldehyde sulfoxylates can the purpose of decolorizing glycerin, and that these afl'ord advantages over the use of animal charcoal for the purpose. Dillicultly soluble, or insoluble, salts of hydrosulfurous acid and of formaldehyde sulfoxylic acid are particularly useful for the purpose of this invention, as, if these be used, the ash contents of the glycerin will not be increased to any great extent.

In carrying out my invention the glycerin can be treated with the hydrosulfite, or with the formaldehyde sulfoxylate, either with or not, although the solutions containin glycerin, such as are obtained during t e manufacture of soa by the saponification of fats and oils caustic alkali, are not well adapted conveniently directly decolorized by the use of hydrosulfites, or formaldehyde sulfoxylates, The said hydrosulfites, or formaldehyde sulfoxylates, can, however, be very conveniently employed to decolorize the glycerin obtained by splitting up fats and oils by heating them with water under pressure and in the presence of an agent such as zinc, zinc oxid, or magnesium oxid, and'in this case the hydrosulfite,

Among the compounds which can be used to this invention I mention sodium hy rosulfite for decolorizing glycerin accordin with a constitution to the formula Na hyde sulfoxylate with a composition prob-.

ably correspondin to NaHSO .CH O, and basic zinc formal ehyde sulfoxylate with a grobably corresponding Specification of Letters Patent. Application filed April 26, 1910. Serial N 0. 557,724.

according to this invention.

or formaldehyde sulfoxylate, can be" added during the splitting sodium formalde- Example 1: Introduce half a part of decrolin (basic zinc formaldehyde sulfoxylate into one hundred parts of dark brown cru e glycerin which has to some extent been purified in the usual manner by means of a salt of iron, or of aluminium, and which is maintained at a temperature of from ninety, to one hundred, degrees centigrade. After a short time a light yellow product is obtained. The way is used can be varied to esses of manufacture, added to the crude glycerin solution, or it can be added while the solution is being evaporated in cacao, or it can be added to the concentrated lycerin. The quantity of decrolin added s liould vary according to the color of.the glycerin to be treated.

Example 2: Add a mixture'of zinc dust, or magnesium oxid, and decrolin, containing about two and a half parts of decrolin, to a mixture of two thousand five hundred partsof cotton seed oil with Water, and heat the whole in an autoclave in the manner generally employed for splitting up cotton seed oil. The glycerin solution thus obtained is colorless, or practically colorless,

whereas if no decrolin is added, it is yellow.

The addition of decrolin, moreover, improves the purity of the fatty acid obtained. Now what I claim is The 'decolorization of glycerin by treating it (either in solution, or not) Wltll a formaldeh'yde sulfoxylate, substantially as hereinbefore described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

' FELIX LINDNER, Witnesses:

ERNEST F. EHRHARDT, .W. W. SCHMIDT.

Patented Mar. 10, 1914.

in which the decrolin;

suit different procfor instance, it can be 

